The Rangers finished last season leaving so many opportunities unclaimed, leaving so many questions forever hovering about how different their Stanley Cup run might have ended.

Too many times, 2 minutes would pass on a power play and the score would remain the same, with the dynamic completely different. Two minutes of failure would lead to many more minutes of frustration and pressure, handing momentum to an opponent that should have been sapped of it.

After failing to convert on 90 power plays (13-for-103, 12.6 percent) in the postseason last year, the Rangers opened this year’s playoffs replicating their power play impotence with painful accuracy, capitalizing on just two of their first 17 opportunities.

“There are so many things that come into play for a good power play,” Martin St. Louis said heading into Game 5 of the Eastern Conference final. “It’s five guys, but we all read off one another. If one guy is off his reads it messes it all up. If your power play is humming, you have five guys doing what they’re supposed to do.”

On the power play, the Rangers are now doing even better than what they’re supposed to do.

After opening 6-of-38 through the first two rounds of the playoffs, the Rangers have scored on 6 of 13 chances over the past three games against the Lightning, having notched a power-play goal in five of the past six games.

The Rangers tallied two power-play goals each in Games 2, 3, and 4, marking the first time they recorded multiple power-play playoff goals in three straight games in 23 years, the first time they scored at least six power-play goals in a series in eight years.

“Sometimes it’s just feeding off one another, and we’re doing a really good job of that,” said St. Louis, whose power-play goal in Game 4 ended his scoreless postseason. “Sometimes it’s winning more face-offs or you’re very efficient where you don’t have to go back all the time and waste some energy on puck retrieval.

“At the end of the day, it’s getting pucks towards the net and getting second and third opportunities.”

Power play opportunities, once a potential catalyst for disintegrating confidence, have helped the Rangers “play with some swagger,” St. Louis said, with six different players scoring on the advantage in the series — St. Louis, Rick Nash, Derek Stepan, Derick Brassard, Chris Kreider and Ryan McDonagh.

Having watched the Rangers’ aggressiveness on the attack increase, and their position inside improve, Tampa Bay coach Jon Cooper said it was imperative for his special teams to give his team a boost.

“Our penalty kill has been a little leaky the last couple games,” Cooper said. “When your special teams are rolling, it helps you roll. Our effort is there, it’s just a little bit execution. We go through these little flurries where the Rangers have taken advantage of us, and we’ve just got to tighten it up.”